Rhodiola crenulata alleviates hypobaric hypoxia-induced brain injury by maintaining BBB integrity and balancing energy metabolism dysfunction.

BACKGROUND/PURPOSE: Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba (R. crenulate), a famous and characteristic Tibetan medicine, has been demonstrated to exert an outstanding brain protection role in the treatment of high-altitude hypoxia disease. However, the metabolic effects of R. crenulate on high-altitude hypoxic brain injury (HHBI) are still incompletely understood. Herein, the anti-hypoxic effect and associated mechanisms of R. crenulate were explored through both in vivo and in vitro experiments. STUDY DESIGN/METHODS: The mice model of HHBI was established using an animal hypobaric and hypoxic chamber. R. crenulate extract (RCE, 0.5, 1.0 and 2.0 g/kg) and salidroside (Sal, 25, 50 and 100 mg/kg) was given by gavage for 7 days. Pathological changes and neuronal apoptosis of mice hippocampus and cortex were evaluated using H&E and TUNEL staining, respectively. The effects of RCE and Sal on the permeability of blood brain barrier (BBB) were detected by Evans blue staining and NIR-II fluorescence imaging. Meanwhile, the ultrastructural BBB and cerebrovascular damages were observed using a transmission electron microscope (TEM). The levels of tight junction proteins Claudin-1, ZO-1 and occludin were detected by immunofluorescence. Additionally, the metabolites in mice serum and brain were determined using UHPLC-MS and MALDI-MSI analysis. The cell viability of Sal on hypoxic HT22 cells induced by CoCl2 was investigated by cell counting kit-8. The contents of LDH, MDA, SOD, GSH-PX and SDH were detected by using commercial biochemical kits. Meanwhile, intracellular ROS, Ca2+ and mitochondrial membrane potential were determined by corresponding specific labeled probes. The intracellular metabolites of HT22 cells were performed by the targeted metabolomics analysis of the Q300 kit. The cell apoptosis and necrosis were examined by YO-PRO-1/PI, Annexin V/PI and TUNEL staining. In addition, mitochondrial morphology was tested by Mito-tracker red with confocal microscopy and TEM. Real-time ATP production, oxygen consumption rate, and proton efflux rate were measured using a Seahorse analyzer. Subsequently, MCU, OPA1, p-Drp1ser616, p-AMPKα, p-AMPKß and Sirt1 were determined by immunofluorescent and western blot analyses. RESULTS: The results demonstrated that R. crenulate and Sal exert anti-hypoxic brain protection from inhibiting neuronal apoptosis, maintaining BBB integrity, increasing tight junction protein Claudin-1, ZO-1 and occludin and improving mitochondrial morphology and function. Mechanistically, R. crenulate and Sal alleviated HHBI by enhancing the tricarboxylic acid cycle to meet the demand of energy of brain. Additionally, experiments in vitro confirmed that Sal could ameliorate the apoptosis of HT22 cells, improve mitochondrial morphology and energy metabolism by enhancing mitochondrial respiration and glycolysis. Meanwhile, Sal-mediated MCU inhibited the activation of Drp1 and enhanced the expression of OPA1 to maintain mitochondrial homeostasis, as well as activation of AMPK and Sirt1 to enhance ATP production. CONCLUSION: Collectively, the findings suggested that RCE and Sal may afford a protective intervention in HHBI through maintaining BBB integrity and improving energy metabolism via balancing MCU-mediated mitochondrial homeostasis by activating the AMPK/Sirt1 signaling pathway.

Deciphering the Efficacy and Mechanism of Astragalus membranaceus on High Altitude Polycythemia by Integrating Network Pharmacology and In Vivo Experiments.

Hypoxic exposure makes plateau migrators susceptible to high altitude polycythemia (HAPC). Astragalus membranaceus (AM) is an edible and medicinal plant with remarkable immunomodulatory activities. The purpose of this study was to discover if AM could be a candidate for the prevention of HAPC and its mechanism. Here, network pharmacology was applied to screen active compounds, key targets, and enriched pathways of AM in the treatment of HAPC. Molecular docking evaluated the affinity between compounds and core targets. Subsequently, the mechanisms of AM were further verified using the hypoxia exposure-induced mice model of HAPC. The network pharmacology analysis and molecular docking results identified 14 core targets of AM on HAPC, which were predominantly mainly enriched in the HIF-1 pathway. In the HAPC animal models, we found that AM inhibited the differentiation of hematopoietic stem cells into the erythroid lineage. It also suppressed the production of erythrocytes and hemoglobin in peripheral blood by reducing the expression of HIF-1α, EPO, VEGFA, and Gata-1 mRNA. Furthermore, AM downregulated the expression of IL-6, TNF-α, and IFN-γ mRNA, thereby alleviating organ inflammation. In conclusion, AM supplementation alleviates hypoxia-induced HAPC in mice, and TNF-α, AKT1, HIF-1α, VEGFA, IL-6, and IL-1B may be the key targets.

Chemical characteristics of Rhodiola Crenulata and its mechanism in acute mountain sickness using UHPLC-Q-TOF-MS/MS combined with network pharmacology analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhodiola crenulata (Hook.f. & Thomson) H.Ohba has a long history of clinical application for the prevention and treatment of acute mountain sickness (AMS) in traditional Chinese medicine. However, gaps in knowledge still exist in understanding the underlying mechanisms of Rhodiola crenulata against AMS. AIMS: To address this problem, a comprehensive method was established by combining UHPLC-Q-TOF-MS/MS analysis and network pharmacology. MATERIALS AND METHODS: The ingredients of Rhodiola crenulata were comprehensively analyzed using UHPLC-Q-TOF-MS/MS method. On this basis, a network pharmacology method incorporated target prediction, protein-protein interaction network, gene enrichment analysis and components-targets-pathways network was performed. Finally, the possible mechanisms were verified through molecular docking, in vitro and in vivo experiments. RESULTS: A total of 106 constituents of Rhodiola crenulata were charactered via UHPLC-Q-TOF-MS/MS. The 98 potentially active compounds out of 106 were screened and corresponded to 53 anti-AMS targets. Gene enrichment analysis revealed that hypoxia and inflammation related genes may be the central factors for Rhodiola crenulata to modulate AMS. Molecular docking revealed that TNF, VEGFA and HIF-1α had high affinities to Rhodiola crenulata compounds. Subsequently, Rhodiola crenulata extract was indicated to inhibit the protein expression level of TNF in hypoxia induced H9c2 cells. Lastly, Rhodiola crenulata extract was further verified to ameliorate heart injury and decreased the heart levels of TNF, VEGFA and HIF-1α in acute hypoxia-induced rats. CONCLUSIONS: This study used UHPLC-Q-TOF-MS/MS analysis and a network pharmacology to provide an important reference for revealing the potential mechanism of Rhodiola crenulata in the prevention and treatment of AMS.

Compound Danshen Dripping Pill inhibits high altitude-induced hypoxic damage by suppressing oxidative stress and inflammatory responses.

CONTEXT: Previous studies indicate that compound Danshen Dripping Pill (CDDP) improves the adaptation to high-altitude exposure. However, its mechanism of action is not clear. OBJECTIVE: To explore the protective effect of CDDP on hypobaric hypoxia (HH) and its possible mechanism. MATERIALS AND METHODS: A meta-analysis of 1051 human volunteers was performed to evaluate the effectiveness of CDDP at high altitudes. Male Sprague-Dawley rats were randomized into 5 groups (n = 6): control at normal pressure, model, CDDP-170 mg/kg, CDDP-340 mg/kg and acetazolamide groups. HH was simulated at an altitude of 5500 m for 24 h. Animal blood was collected for arterial blood-gas analysis and cytokines detection and their organs were harvested for pathological examination. Expression levels of AQP1, NF-κB and Nrf2 were determined by immunohistochemical staining. RESULTS: The meta-analysis data indicated that the ratio between the combined RR of the total effective rate and the 95% CI was 0.23 (0.06, 0.91), the SMD and 95% CI of SO2 was 0.37 (0.12, 0.62). Pre-treatment of CDDP protected rats from HH-induced pulmonary edoema and heart injury, left-shifted oxygen-dissociation curve and decreased P50 (30.25 ± 3.72 vs. 37.23 ± 4.30). Mechanistically, CDDP alleviated HH-reinforced ROS by improving SOD and GPX1 while inhibiting pro-inflammatory cytokines and NF-κB expression. CDDP also decreased HH-evoked D-dimer, erythrocyte aggregation and blood hemorheology, promoting AQP1 and Nrf2 expression. DISCUSSION AND CONCLUSIONS: Pre-treatment with CDDP could prevent HH-induced tissue damage, oxidative stress and inflammatory response. Suppressed NF-κB and up-regulated Nrf2 might play significant roles in the mechanism of CDDP.

Highland mate: Edible and functional foods in traditional medicine for the prevention and treatment of hypoxia-related symptoms.

The highlands evoke both fascination and awe. Regardless of the reason to live in the highlands, symptoms related to altitude sickness are unbearable because of low atmospheric pressure, low oxygen concentration, strong ultraviolet radiation, cold, and psychological factors. Food and herbal medicines and/or health-care foods have protected highland dwellers owing to their multisystem regulation. These versatile products combine health-care properties with medical values by enhancing immunity, relieving physical fatigue, improving sleep, and augmenting hypoxia tolerance, with rare side effects. We therefore aimed to provide a more comprehensive analysis of these nutraceuticals, which can be used to prevent and treat symptoms of altitude hypoxia in the Chinese market. Finally, we dissect a new perspective for their promotion and development from molecular aspects.

iTRAQ-based quantitative proteomic analysis of the improved effects of total flavones of Dracocephalum Moldavica L. in chronic mountain sickness.

To use isobaric tags for relative and absolute quantification (iTRAQ) technology to study the pathogenesis of chronic mountain sickness (CMS), identify biomarkers for CMS, and investigate the effect of total flavones of Dracocephalum moldavica L. (TFDM) on a rat model of CMS. We simulated high altitude hypobaric hypoxia conditions and generated a rat model of CMS. Following the administration of TFDM, we measured the pulmonary artery pressure and serum levels of hemoglobin (Hb), the hematocrit (Hct), and observed the structure of the pulmonary artery in experimental rats. Furthermore, we applied iTRAQ-labeled quantitative proteomics technology to identify differentially expressed proteins (DEPs) in the serum, performed bioinformatics analysis, and verified the DEPs by immunohistochemistry. Analysis showed that the pulmonary artery pressure, serum levels of Hb, and the Hct, were significantly increased in a rat model of CMS (P < 0.05). Pathological analysis of lung tissue and pulmonary artery tissue showed that the alveolar compartment had obvious hyperplasia and the pulmonary artery degree of muscularization was enhanced. Both pulmonary artery pressure and tissue morphology were improved following the administration of TFDM. We identified 532 DEPs by quantitative proteomics; gene ontology (GO)and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis further revealed that metabolic pathways associated with coagulation and complement play crucial roles in the occurrence of CMS. Immunohistochemistry verified that several DEPs (α-1-acid glycoprotein, collagen, fibulin, haptoglobin, PLTP, and TAGLN2) are important biological markers for CMS. Our analyses demonstrated that TFDM can improve CMS and exert action by influencing the metabolic pathways associated with coagulation and complement. This process relieves pulmonary artery pressure and improves lung function. We also identified that α-1-acid glycoprotein, collagen, fibulin, haptoglobin, PLTP, and TAGLN2 may represent potential biomarkers for CMS.

Efficacy of Shouzhangshen (Rhizoma Gymnadeniae Crassinervidis) extract against acute high altitude hypoxia-induced brain injury in mice.

OBJECTIVE: To evaluate the protective effect of Shouzhangshen (Rhizoma Gymnadeniae Crassinervidis) extract against acute high altitude hypoxia-induced brain injury in mice. METHODS: Sixty C57BL/6J mice were selected and assigned to six groups (n = 10): normal control group, low-pressure hypoxia group, positive control group (dexamethasone 500 mg/kg), and three groups treated with Shouzhangshen extract (250, 500, and 750 mg/kg, respectively). The Morris water maze test was performed to evaluate alterations in spatial learning and memory deficits. Nissl staining was performed to detect Nissl bodies and neuron damage. Hypoxia-inducible factor (HIF)-1α, interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), and malondialdehyde (MDA) expression in brain tissue and serum, as well as superoxide dismutase (SOD) and glutathione (GSH) activity in brain tissues were measured by enzyme-linked immunosorbent assays, quantitative real-time-polymerase chain reaction and western blots. RESULTS: The Morris water maze test results showed that Shouzhangshen extract can significantly reduce the latency and swimming distance to escape onto a visible platform, increase neuron density and hierarchy and the number of pyramidal neurons, and decrease the expression of HIF-1α, IL-1ß, TNF-α, and VEGF mRNAs and proteins in both brain tissue and serum (P < 0.05). Furthermore, significantly lower MDA expression and higher GSH activity were detected in the three groups treated with Shouzhangshen compared with the low-pressure hypoxia group (P < 0.05). However, no significant alteration was observed for SOD activity (P > 0.05). CONCLUSION: Our findings suggest that Shouzhangshen extract may have a significant effect on acute high altitude hypoxia-induced brain injury in mice.

Is carbonic anhydrase inhibition useful as a complementary therapy of Covid-19 infection?

The ongoing Covid-19 is a contagious disease, and it is characterised by different symptoms such as fever, cough, and shortness of breath. Rising concerns about Covid-19 have severely affected the healthcare system in all countries as the Covid-19 outbreak has developed at a rapid rate all around the globe. Intriguing, a clinically used drug, acetazolamide (a specific inhibitor of carbonic anhydrase, CA, EC 4.2.1.1), is used to treat high-altitude pulmonary oedema (HAPE), showing a high degree of clinical similarities with the pulmonary disease caused by Covid-19. In this context, this preliminary study aims to provide insights into some factors affecting the Covid-19 patients, such as hypoxaemia, hypoxia as well as the blood CA activity. We hypothesise that patients with Covid-19 problems could show a dysregulated acid-base status influenced by CA activity. These preliminary results suggest that the use of CA inhibitors as a pharmacological treatment for Covid-19 may be beneficial.

Qi-Long-Tian formula extract alleviates symptoms of acute high-altitude diseases via suppressing the inflammation responses in rat.

BACKGROUND: Chinese Yunnan Province, located in the Yunnan-Guizhou Plateau, is a famous tourist paradise where acute high-altitude illness common occurs among lowland people visitors due to non-acclimatization to the acute hypobaric hypoxia (AHH) conditions. Traditional Chinese medicine, such as Qi-Long-Tian (QLT) formula, has shown effectiveness and safety in the treatment of acute high-altitude diseases. The aim of this study was to clarify the therapeutic mechanisms of this traditional formula using a rat model in a simulated plateau environment. METHODS: Following testing, lung tissue samples were evaluated by hematoxylin-eosin staining and for biochemical characteristics. mRNA-Seq was used to compare differentially expressed genes in control rats, and in rats exposed to AHH and AHH with QLT treatment. RESULTS: Inflammation-related effectors induced following QLT treatment for AHH included MMP9 and TIMP1, and involved several phosphorylation signaling pathways implicated in AHH pathogenesis such as PI3K/AKT and MAPK signaling. CONCLUSION: This study provides insights into the major signaling pathways induced by AHH and in the protective mechanisms involved in QLT formula activity.

Tetrahydrocurcumin mitigates acute hypobaric hypoxia-induced cerebral oedema and inflammation through the NF-κB/VEGF/MMP-9 pathway.

High-altitude cerebral oedema (HACE) is a potentially fatal manifestation of high-altitude sickness and is caused partly by inflammation and the blood-brain barrier disruption. Tetrahydrocurcumin (THC) has been reported to exert effective antioxidative and anti-inflammatory effects; This study sought to elucidate the underlying mechanism of THC in mitigating HACE using a mouse model. Our results revealed that prophylactic administration of THC (40 mg/kg) for 3 days significantly alleviated the increase in brain water content (BWC), interleukin-1ß (IL-1ß) and TNF-α levels caused by acute hypobaric hypoxia (AHH). Additionally, superoxide dismutase (SOD) activity was increased by THC to enhance the ability to resist hypoxia. Histological and ultrastructural analysis of the cerebrum revealed that THC administration mitigated AHH-induced pericellular oedema and reduced the perivascular space, resulting in the simultaneous remission of oedema and protection of mitochondria in the cerebrum. In vitro, astrocytes exposed to hypoxia (4% O2 ) for 24 hr exhibited and increase in IL-1ß expression followed by an increase in vascular endothelial growth factor (VEGF) levels. Furthermore, THC administration remarkably downregulated VEGF, matrix metallopeptidase-9 (MMP-9), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) expression, both in vivo and in vitro. Our data highlight the potential prophylactic activity of THC in HACE, it effectively mitigates AHH-induced cerebral oedema and inflammation is associated with the inhibition of the NF-κB/ VEGF/MMP-9 pathways.

Compound Danshen Dripping Pill Promotes Adaptation to Acute High-Altitude Exposure.

Li, Zongbin, Jun Guo, Chunwei Liu, Yajun Shi, Yang Li, Jinli Wang, Dandan Li, Jing Wang, and Yundai Chen. Compound Danshen Dripping Pill promotes adaptation to acute high-altitude exposure. High Alt Med Biol. 21:258-264, 2020. Background: In this study, we aimed to investigate whether the traditional Chinese medicine, Compound Danshen Dripping Pill (CDDP), can prevent acute mountain sickness (AMS). We allocated CDDP and matching placebos to 160 volunteers before they ascended to a high altitude. Treadmill exercise tests, echocardiography, blood routine examinations, biochemical analysis, and blood gas analysis were performed upon arrival at high altitude. The primary outcome included incidence of AMS, exercise times, and metabolic equivalents (METs) of treadmill exercise tests. Second endpoints included the heart rates and rate-pressure product (RPP) before and after treadmill exercise tests. Results: After high-altitude exposure, the incidence of AMS in the CDDP group was lower than that in the placebo group (48.6% vs. 67.6%, p = 0.022). The exercise time of the treadmill exercise test was significantly longer (507 ± 77.9 seconds vs. 457 ± 90.8 seconds, p = 0.004), the heart rate was lower (pre-exercise: 91.8 ± 11.7 beats/min vs. 97.2 ± 12.7 beats/min, p = 0.016; postexercise: 114 ± 22.2 beats/min vs. 121 ± 22.6 beats/min, p = 0.019), the pre-exercise and postexercise RPP were lower (pre-exercise: 1.13 × 104 ± 1.68 × 103 mmHg·beats/min vs. 1.23 × 104 ± 1.84 × 103 mmHg·beats/min, p = 0.027; postexercise: 1.19 × 104 ± 1.75 × 103 mmHg·beats/min vs. 1.31 × 104 ± 2.00 × 103 mmHg·beats/min, p = 0.002), and the MET value of the treadmill exercise test was significantly higher (9.93 ± 1.18 METs vs. 9.31 ± 1.52 METs, p = 0.037) in the CDDP group. Discussion: CDDP decreases the incidence of AMS and enhances exercise tolerance greater than placebo after high-altitude exposure. CDDP decreases the heart rate and myocardial oxygen consumption, increases the levels of hemoglobin, hematocrit, and antioxidant factors, and decreases the levels of inflammatory factors, which may explain the roles of CDDP in improving the adaptation to high-altitude exposure.

Systematically investigating the pharmacological mechanism of Dazhu Hongjingtian in the prevention and treatment of acute mountain sickness by integrating UPLC/Q-TOF-MS/MS analysis and network pharmacology.

Members of the genus Rhodiola L. have been widely used in Tibetan medicines for preventing and treating acute mountain sickness (AMS) for a long time. However, the pharmacological mechanisms of these medicines in treating AMS remain unclear. To address this problem, an integrative method combining ultra-performance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS/MS)analysis and network pharmacology was employed. First, the chemical profiles of Dazhu Hongjingtian (DZ, a Chinese medicine preparation composed of R. kirilowii (Regel) Maxim) were identified or tentatively characterized. Second, the targets of DZ were predicted using the SwissTargetPrediction and STITCH databases; the targets of AMS were also collected from the Drugbank and TTD databases. Then, networks between targets and compounds or diseases were constructed by Cytoscape 3.6.1. Third, GO and pathway enrichment analyses were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID). As a result, 40 ingredients of 53 compounds in DZ might be biologically active. These activities were related to the regulatory effects of the ingredients on 68 significant signaling pathways, such as the inflammation pathway, apoptosis pathway, HIF-1 signaling pathway, and others, by targeting 33 proteins, including PTGS2 and PTGS1, ALOX5 and ALOX15, BCL2 and BCL2L1, the protein kinase C (PKC) family and HIF1A, among others.

Trans-Himalayan Phytococktail Confers Protection Against Hypobaric Hypoxia-Induced Hippocampal Neurodegeneration and Memory Impairment in Male Sprague Dawley Rats.

Background: Exposure to hypobaric hypoxia (HH) has been reported to cause neurodegeneration and memory impairment. Hippophae rhamnoides, Prunus armeniaca, and Rhodiola imbricata, the indigenous plants of Indian Trans-Himalaya are widely used in traditional Tibetan and Amchi system of medicine. These are rich sources of diverse bioactive metabolites having prophylactic and therapeutic uses against a wide array of neurodegenerative diseases. The objective of this study was to elucidate the prophylactic and neuroprotective efficacy of formulated phytococktail (PC) against simulated HH-induced neurodegeneration in male Sprague Dawley (SD) rats. Materials and Methods: A PC containing H. rhamnoides fruit pulp, P. armeniaca fruit pulp, and R. imbricata dry root extract (100:50:1) was formulated. The neuroprotective efficacy of PC was evaluated in male SD rats following exposure to 7 day HH at simulated altitude (25,000 ft, 282 mm Hg). Rats were divided into four groups viz., normoxia group (NOR), normoxic group treated with PC (NORPC), 7 day hypoxic group treated with vehicle (7DH), and 7 day hypoxic group treated with PC (7DHPC). Memory impairment and neuromorphological alterations were measured. Targeted protein expression was analyzed by immunoblotting study. Results: PC supplementation significantly reduced the oxidative stress markers during exposure to HH. Spatial memory impairment by HH was significantly ameliorated by PC. HH-induced augmented pyknosis, decreased dendritic arborization, and increased Hoechst-positive neurons in hippocampal CA3 region were significantly ameliorated by PC. Immunoblotting study showed upregulation of BDNF and TrkB expression by PC. PC also prevented the hippocampal neurodegeneration by activating the PI3K/AKT signaling pathway, which leads to GSK-3ß inactivation by its phosphorylation and alleviation of hippocampal Caspase3 expression leading to inhibition of apoptotic neuronal cell death. Conclusion: The present study advocates the potential role of PC as an effective neuroprotective supplement in preventing HH-induced neurodegeneration. Activation of the PI3K/Akt pathway through BDNF/TrkB interaction following PC supplementation after exposure to HH inhibits hippocampal neuronal apoptosis and memory impairment.

Phytochemistry and Biological Activities of Werneria and Xenophyllum species / Fitoquímica y actividades biológicas de especies de Werneria y Xenophyllum

Plants of the genera Werneria (Asteraceae) and Xenophyllum (genus extracted from Werneria) are used in traditional medicine of Latin America for the treatment of mountain sickness, hypertension and gastrointestinal disorders. Only a small number of species of these genera have been studied, leading to the isolation of compounds belonging to the classes of benzofurans, chromenes, acetophenones, coumarates, diterpenes and pyrrolizidine alkaloids. Some of the plant extracts and/or compounds have shown antimicrobial, anti-HIV, hypotensive and photoprotective activities.

Las plantas de los géneros Werneria (Asteraceae) y Xenophyllum (género extraido de Werneria) son usadas en la medicina tradicional de América Latina para el tratamiento del mal de montaña, hipertensión y desórdenes gastrointestinales. Solo un pequeño número de especies de estos géneros ha sido investigado, lográndose aislar compuestos que pertenecen a las clases de benzofuranos, cromenos, acetofenonas, cumaratos, diterpenos y alcaloides pirrolizidínicos. Algunos de los extractos y/o compuestos de dichas plantas han mostrado actividades antimicrobianas, anti-HIV, hipotensoras y fotoprotectoras.

Phenylethanoid glycosides of Phlomis younghusbandii Mukerjee ameliorate acute hypobaric hypoxia-induced brain impairment in rats.

High altitude cerebral edema (HACE), whose development process is associated with oxidative stress and inflammatory response, is a life-threatening condition caused by rapid ascent speed to high altitudes. Phenylethanoid glycosides (PhGCs) are primary active constituents isolated from Phlomis younghusbandii Mukerjee that reportedly exhibit potent anti-oxidant and anti-inflammatory activities. The present study aims to investigate the protective effect of phenylethanoid glycosides (PhGCs) from P. younghusbandii in acute hypobaric hypoxia (AHH) - stimulated HACE rats and its underlying mechanisms. The expression of pro-inflammatory cytokine levels (IL-1ß, TNF-α, and IL-6) was detected by RT-PCR and ELISA at mRNA and protein levels in brain tissues. Western blotting was carried out to measure the major protein levels (IL-1ß, TNF-α, and NF-κB) in brain tissues. The oxidative stress biomarkers (MDA, SOD, and GSH) were evaluated using kits. Results demonstrate that PhGCs significantly improved pathological changes in brain tissues, reduced the brain's water content, and attenuated the production and mRNA expression of pro-inflammatory cytokines. Furthermore, the increased oxidative stress and the decrease in anti-oxidant stress system under the AHH condition were also abrogated reversely through PhGCs treatment by elevating the levels of SOD and GSH and suppressing the accumulation of MDA. Simultaneously, there was also a significant reduction in NF-κB, IL-1ß, and TNF-α protein expression levels in brain tissues, suggesting that blocking the NF-κB signaling pathway activation prevented the production of pro-inflammatory cytokines. Taken together, these findings indicate that PhGCs may afford a protectively intervene in HACE through the suppression of oxidative stress and inflammatory response via the inhibition of the NF-κB signaling pathway, indicating that PhGCs are promising agents for the treatment of acute HACE.

[Effects of Salvia przewalskii Maxim. on high-altitude pulmonary hypertension in rats and its mechanism].

OBJECTIVE: To investigate the interventive effects of Salvia przewalskii Maxim.(SPM)on high-altitude pulmonary hypertension(HAPH)in rats and possible mechanism. METHODS: The male SD rats were randomly divided into the control group, the hypoxia group and SPM(0.5 g/kg,1 g/kg and 2 g/kg) group. There were 14 rats in each group. The rats in control group were feed in Xining(with an altitude about 2 260 m), and the other group rats were all feed in Maduo county people's hospital(with an altitude about 4 260 m). The rats in SPM groups were treated with SPM at the doses of 0.5 g/kg,1 g/kg and 2 g/kg by gavage respectively (100 g/ml). The rats in control and the hypoxia groups were received equal volume of distilled water, once a day. After 4 weeks, the mean pulmonary artery pressure (mPAP) of rats was measured and the same part of lung tissue of each rat was collected and stored in liquid nitrogen. Then the relative mRNA expression levels of the proliferation cell nuclear antigen(PCNA), the cell cycle dependent kinase 4(CDK4), CyclinD1, RhoA, ROCK1, ROCK2 in lung tissues of each group rats were all tested by RT-PCR. RESULTS: Compared with the control group, the mPAP and the relative mRNA expression levels of PCNA, CDK4, CyclinD1, RhoA, ROCK1 and ROCK2 were increased significantly in the hypoxia group(P＜0.01). Compared with the hypoxia group, the mPAP and the relative mRNA expression levels of PCNA, CDK4, CyclinD1, RhoA, ROCK1 and ROCK2 in the lung tissues of the SPM group rats were all decreased significantly(P＜ 0.05 or P＜0.01). CONCLUSION: SPM can prevent the HAPH in rats, and the mechanisms may be related to the inhibition of the excessive proliferation of smooth muscle cells in pulmonary artery and the excessive activation of the RhoA/Rho kinase(ROCK) signaling pathway.

Understanding molecular mechanisms of Rhodiola rosea for the treatment of acute mountain sickness through computational approaches (a STROBE-compliant article).

Rhodiola rosea has been used in the treatment of acute mountain sickness (AMS) for a long time, but the mechanism of its action is not still completely clear. In this paper, the therapeutic mechanism of R rosea for AMS was investigated by analysis of the relationship between R rosea compositions and hypoxia-inducible factor 1 (HIF-1) degradation pathway.System biology and network biology, computational approaches were used to explore the molecular mechanisms of traditional Chinese medicine (TCM).Our results showed that chemical compositions of R rosea could inhibit the targets of HIF-1 degradation pathway in multi-composition/multi-target ways.We conclude that the 18 components with more than 2 targets and 5 targets (arrest-defective-1 [ARD1], forkhead transcription factor [FOXO4], osteosarcoma-9 [OS-9], prolyl hydroxylase 2 [PHD2], human double minute 2 [Hdm2]) deserve to be noticed, and PHD2, receptor for activated C-kinase1 (RACK1) and spermidine/spermine-N1-acetyltransferase-1 (SSAT1) may be the targets of active ingredients of rhodionin, rhodiosin, and rhodiolatuntoside, respectively.

Redox-regulation of haemostasis in hypoxic exercising humans: a randomised double-blind placebo-controlled antioxidant study.

KEY POINTS: In vitro evidence has identified that coagulation is activated by increased oxidative stress, though the link and underlying mechanism in humans have yet to be established. We conducted the first randomised controlled trial in healthy participants to examine if oral antioxidant prophylaxis alters the haemostatic responses to hypoxia and exercise given their synergistic capacity to promote free radical formation. Systemic free radical formation was shown to increase during hypoxia and was further compounded by exercise, responses that were attenuated by antioxidant prophylaxis. In contrast, antioxidant prophylaxis increased thrombin generation at rest in normoxia, and this was normalised only in the face of prevailing oxidation. Collectively, these findings suggest that human free radical formation is an adaptive phenomenon that serves to maintain vascular haemostasis. ABSTRACT: In vitro evidence suggests that blood coagulation is activated by increased oxidative stress although the link and underlying mechanism in humans have yet to be established. We conducted the first randomised controlled trial to examine if oral antioxidant prophylaxis alters the haemostatic responses to hypoxia and exercise. Healthy males were randomly assigned double-blind to either an antioxidant (n = 20) or placebo group (n = 16). The antioxidant group ingested two capsules/day that each contained 500 mg of l-ascorbic acid and 450 international units (IU) of dl-α-tocopherol acetate for 8 weeks. The placebo group ingested capsules of identical external appearance, taste and smell (cellulose). Both groups were subsequently exposed to acute hypoxia and maximal physical exercise with venous blood sampled pre-supplementation (normoxia), post-supplementation at rest (normoxia and hypoxia) and following maximal exercise (hypoxia). Systemic free radical formation (electron paramagnetic resonance spectroscopic detection of the ascorbate radical (A•- )) increased during hypoxia (15,152 ± 1193 AU vs. 14,076 ± 810 AU at rest, P < 0.05) and was further compounded by exercise (16,569 ± 1616 AU vs. rest, P < 0.05), responses that were attenuated by antioxidant prophylaxis. In contrast, antioxidant prophylaxis increased thrombin generation as measured by thrombin-antithrombin complex, at rest in normoxia (28.7 ± 6.4 vs. 4.3 ± 0.2 µg mL-1 pre-intervention, P < 0.05) and was restored but only in the face of prevailing oxidation. Collectively, these findings are the first to suggest that human free radical formation likely reflects an adaptive response that serves to maintain vascular haemostasis.

Rhodiola crenulata extract counteracts the effect of hypobaric hypoxia in rat heart via redirection of the nitric oxide and arginase 1 pathway.

BACKGROUND: Rhodiola crenulata is traditionally used as a folk medicine in Tibet for preventing high-altitude illnesses, including sudden cardiac death (SCD). The cardio-protective effects of Rhodiola crenulata root extract (RCE) against hypoxia in vivo have been recently confirmed. However, the way in which RCE produces these effects remains unclear. The present study is designed to confirm the protective effects of RCE on the heart in acute hypobaric hypoxia exposure and examine the mechanisms by which this occurs. METHODS: Sprague-Dawley (SD) rats were pretreated with or without RCE and then exposed to a simulated altitude of 8000 m in a hypobaric hypoxia chamber for 9 h. The expression of cardiac arginase 1 (Arg-1) and endothelial nitric oxide synthase (eNOS) and the activity of associated signaling pathways was examined. RESULTS: Hypoxia reduced cardiac eNOS phosphorylation and increased Arg-1 expression, but both responses were reversed by RCE pre-treatment. In addition, RCE decreased the hypoxia-induced oxidative stress markers of reactive oxygen species (ROS) production, malondialdehyde (MDA) level, and protein carbonyl content. Furthermore, RCE protected cardiomyocytes from hypoxia-induced cardiac apoptosis and restored the phosphorylation level of AKT and p38 MAPK as well as the superoxide dismutase 2 (SOD2) content in hypoxic animals. CONCLUSION: The findings provide evidence that the effects of Rhodiola crenulata against altitude illness are partially mediated by modulation of eNOS and Arg-1 pathways in the heart.

Protective effects of traditional Tibetan medicine Zuo-Mu-A Decoction () on the blood parameters and myocardium of high altitude polycythemia model rats.

OBJECTIVE: To explore the protective effects of Tibetan medicine Zuo-Mu-A Decoction (, ZMAD) on the blood parameters and myocardium of high altitude polycythemia (HAPC) model rats. METHODS: Forty male Wistar rats were randomly divided into 4 groups by a random number table, including the normal, model, Rhodiola rosea L. (RRL) and ZMAD groups (10 in each group). Every group was raised in Lhasa to create a HAPC model except the normal group. After modeling, rats in the RRL and the ZMAD groups were administered intragastrically with RRL (20 mL/kg) and ZMAD (7.5 mL/kg) once a day for 2 months, respectively; for the normal and the model groups, 5 mL of distilled water was administered intragastrically instead of decoction. Then routine blood and hematologic rheology parameters were taken, levels of erythropoietin and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were tested, and ultrastructural change in the left ventricular myocardium was observed using transmission electron microscopy. RESULTS: Compared with the model group, ZMAD significantly reduced the red blood cell count, hemoglobin levels, whole blood viscosity at low/middle shear rates, plasma viscosity, erythrocyte electrophoretic time, erythropoietin and 8-OHdG levels, and also increased the erythrocyte deformation index (P<0.05). There was no difference in all results between the RRL and the ZMAD groups. The cardiac muscle fibers were well-protected, mitochondrial matrix swelled mildly and ultrastructure changes were less prominent in the ZMAD group compared with the model group. CONCLUSION: ZMAD has significant protective effects on the blood parameters against HAPC, and also has the beneficial effect in protecting against myocardial injury.